You should use "epoll" instead of "poll" and turn on "sendfile" if you server also serve static files.
Consider to install wp-cache to avoid generating the page again and agin.
What is the "max connection" for lsphp? do not set it too large to have your server start to use swap.

Have you tried memcached to cache some part of your page to avoid querying the DB again and again?
What is your current memory usage as shown in "top" ouput?
From the real time report of LiteSpeed web console, what's requests/s of your server and lsphp application? Please post the statistic information of lsphp.

You need to exclue the cache and buffer memory from used memory.
Do you mean that you use APC as an object cache inaddition to opcode cache?
If your PHP was built with memcache extension, you should be able to use it.

I need the lsphp application statistics at the bottom of the report page.

Increased load does not matter much, and it is normal to get higher load when you increase it. There is a sweet spot somewhere. Just do not overtune it.
That's pretty much what can be done from litespeed side, you can continue to improve your PHP script in order to get better performance out of it.